Advances in Understanding the Physiological and Molecular Responses of Sugar Beet to Salt Stress

Abstract

Soil salinity is a major environmental stress on crop growth and productivity. A better understanding of the molecular and physiological mechanisms underlying salt tolerance will facilitate efforts to improve crop performance under salinity. Sugar beet is considered to be a salt-tolerant crop, and it is therefore a good model for studying salt acclimation in crops. Recently, many determinants of salt tolerance and regulatory mechanisms have been studied by using physiological and ‘omics approaches. This review provides an overview of recent research advances regarding sugar beet response and tolerance to salt stress. We summarize the physiological and molecular mechanisms involved, including maintenance of ion homeostasis, accumulation of osmotic-adjustment substances, and antioxidant regulation. We focus on progress in deciphering the mechanisms using ‘omic technologies and describe the key candidate genes involved in sugar beet salt tolerance. Understanding the response and tolerance of sugar beet to salt stress will enable translational application to other crops and thus will have significant impacts on agricultural sustainability and global food security.

Physiological and Transcriptome Analysis of Sugar Beet Reveals Different Mechanisms of Response to Neutral Salt and Alkaline Salt Stresses

“…Sugar beet inherited the salt tolerance trait from its ancestor sea beet (B. vulgaris ssp. Maritima), which grows naturally along the Atlantic coasts of Western Europe (Lv et al, 2019). We consistently found that low concentrations of neutral and alkaline salts stimulated growth.…”

“…To cope with saline-alkaline stress, plants have evolved a variety of strategies to adapt to the saline-alkali environments. In general, the adaptive strategies of plants to neutral salt stress mainly include accumulating of osmotic adjustment substances, enhancing the reactive oxygen species (ROS) scavenging system and maintaining ion homeostasis (Yang and Guo, 2018b;Lv et al, 2019). Many genes associated with these salt tolerant physiological and biochemical processes were identified through genomics or transcriptomic tools (Prerostova et al, 2017;Geng et al, 2019).…”

Transcriptomic and metabolomic analyses reveal mechanisms of adaptation to salinity in which carbon and nitrogen metabolism is altered in sugar beet roots

“…The salt tolerance of sugar beet is a complex trait that is determined by many physiological and metabolic pathways, including an increased content of compatible solutes [22]. Lv et al believe that the most important factor for beet salt tolerance may be osmotic adjustment [40].…”

Transcriptome Analysis of Salt-Sensitive and Tolerant Genotypes Reveals Salt-Tolerance Metabolic Pathways in Sugar Beet

“…The accumulation of ions (Na + and Cl − ) is toxic to cells by decreasing the water potential and stomatal conductance. At the same time, a low water potential in saline soil makes it difficult for the roots of plants to absorb water, causing physiological drought [3]. However, in order to survive under salt stress, plants adapt a series of complex strategies, including the efflux of ions, increased antioxidant enzyme activity and synthesis of osmotic adjustment proteins to cope with the stress.…”